NME has reported on a study that claims pop music has grown darker and more depressing over the last 50 years. The new study was published in the Psychology of Aesthetics, Creativity, and the Arts journal and conducted by Glenn Schellenberg and Christian von Scheve.

Together, the duo picked apart 1,010 songs taken from Billboard’s annual Top 40 list between the years of 1965 and 2009 to discern the mode and tempo of each track. The findings showed that songs in minor-mode, often associated with more depressing pop tunes, doubled during the past 5 decades. In the meantime, the frequency of slower tracks also grew, reaching a crescendo in the 90s.

The study also claims that fast-mode, ‘happy’ high tempo songs have dropped during the same period while songs in general have increased in length. Schellenberg and von Scheve have posed a handful of possibilities for why their study has found pop music to be increasingly depressing, citing factors such as consumerism and individualism.

In regards to how the co-authors conducted their study, the duo wrote:

We examined whether emotional cues in American popular music have changed over time, predicting that music has become progressively more sad-sounding and emotionally ambiguous. Our sample comprised over 1,000 Top 40 recordings from 25 years spanning five decades.

Over the years, popular recordings became longer in duration and the proportion of female artists increased… In line with our principal hypotheses, there was also an increase in the use of minor mode and a decrease in average tempo, confirming that popular music became more sad-sounding over time. Decreases in tempo were also more pronounced for songs in major than in minor mode, highlighting a progressive increase of mixed emotional cues in popular music.